My opinion, as incorrectas it may be, is that the main faults in your character can be found in her personality. Although you state she isn't strong mentally and cries a lot, neither of these are really a fault in personality. Flaws in personality generally go more along the lines of arrogant or possesive, and believe me when I say we all have them.

You also mentions she is naive, freezes up around others and sometimes even faints. I hate to say it but there are several sueish tendancies in all of these 'traits'. However there are also some signs of a promising character...if you just delve a little deeper. What parts of her perosnality cause her to be so nervous around others? Would these be consdiered unfortunate traits or flaws? How can you use these to balance out her good traits? Will it make for a believable character?

If you begin to ask yourself questions about your character you can really get to know them. Once you think you have a personality it may help to image your character in certain scenarios and the way they might react, just to feel out their personality a little.

Hope some of this helps, and I didn't come out sounding like a complete prat. I'm still learning myself >.<